mr conditioning



March 29, 1938. F. R. BlcHowsKY AIR CONDITIONING Filed Nov. 7, 1934 W W f M M6 V W Wd f M .A 7 f W15 l w f d? f M ya z v 2, f fr., z A y /WMM a M w, w, M b N/ M z fw U m.. 3 AW MM V y a, .MU fm N M ad E .W if a 0 M E W d a N/ /k M 7 W 7 op C w 0 W M i Patented Mar. 29, 1938 UNITED ysTATlazs PAENT OFFICE AIR. CONDITIONING Francis R. Bichowsky, Toledo, 0o

Application November 7, 1934, Serial No. "151,958

'i claim.

This inventionl relates to air conditioning of enclosures or places of occupancy such as public buildings, houses, theatres, and the like, wherein it is desired to obtain and maintain a predetermined condition of the air.I One of the objects' of this invention is to provide a method and means of producing more comfortableconditions in places of occupancy and of reducing the cost of air conditioning in such places.

Another object of this invention is to provide methods and apparatus for conditioning air jointly by means of dehydrating .apparatus and by means of cooling apparatus, both of which may be automatically controlled to produce the desired conditions.

Further objects and advantages will be apparent from the full disclosure of the following speciiication and the drawing forming a part thereof, wherein, Fig. 1 represents, in somewhat diagrammatic form, a preferred embodiment of the invention; and Fig. 2 shows a psychrometric chart illustrating one mode of operation oi the invention.

The usual mode of air conditioning buildings involves circulation of the air from the space to be occupied into a chamber where the airis contacted with a cold media of suiiciently low temperature to condense a portion of the water on the cold media. This cold and partially dry air is then tempered by mixing with a portion of the air which is circulated and which has not been refrigerated and reintroduced into the building. Such a system has the disadvantage that by it it is only possible to control the humidity of the space conditioned within a limited degree and it has the further disadvantage that since the use of refrigeration is a relatively expensive way of removing water from air the operating cost of the system is unduly high.

In accordance with my invention, the cooling and drying of the air are accomplished separately in such a manner as to reduce the total cooling load and toallow a more comfortable nal condition of temperature and humidity and to simplify construction.

In the drawing, the spaces l and 2 are spaces of occupancy to be conditioned. Conditioned air enters these spaces through the openings i0 and Il which are connected to the ducts i2 and I3. In the spaces l and 2, due to the heat of occupancy and due to heat gains and other causes, the air in the space picks up heat and moisture which must b e removed. This heat and moisture is in part removed by venting a portion of the air through the Vent M t0 the (Cl. QSI-lil.)

outside. The remaining portion of heat and moisture is removed by passing a large portion of the air through the vents t, 5 and 6, the ducts l and 2t, through a chamber t, in which it is cooled but in which, according to the mode of 5 operation of my invention, no moisture 'is removed. This cooled air is returned by fan IG or other means through the ducts i2 and i3 into the spaces to be cooled and air conditioned. It constitutes the main stream of circulating air. 10 In order to balance the quantity of air introduced into the room and the quantity of air leaving the room, there is provided a third passage for air il, iii, 20, adapted to lead in. fresh air from the outside and after treating it to mix it with 15 air entering through the duct 2i in the mixing space Id. The ducts entering into the mixing space ld, namely, the entrance 2t for the outside air and the entrance 2i for the recirculating air may be provided with dampers 22 and 23 to con- 2o trol the proportion of -air entering by these two paths. As has been heretofore described, the cooling surfaces in the space t, namely, the iin type coolers 3l, 32 are at all times maintained above the dew point oi the air entering the chamber t, and for this pur a device Vl5 sensitive to changes in dew point may be provided adapted, through connection with the means Mi, to control the temperature of the cooling agent entering the coolers 3i, d2. .ln order to reduce a@ the humidity of the air in the space, and to remove the water taken up in that space, I introduce in the passage id through which air enters the cooling space itl by the passage it, a zone tt in which the air is dried by being con- 35 tacted with a liquid drying agent in accordance with the method and principle set forth in my U. S. Patent 1,992,177. For cple, the air is contacted' with a drying solution of lithium chloride introduced in the form of spray through the M, nozzles di and 52. 'The liquid may be collected in the sump dt and be recirculated from the sump to the nozzles 5l and t2 by means oi a pump 5t' and the piping 55. The concentration of the solution in the sump t3 may be controlled from 45 time to time by withdrawing a portion of the liquid in the sump to the regenerating boiler Si where the accumulated water 5lslboiled off in the form of steam through the pipe 5t, the heat necessary for this operation being supplied 50 through the burner 59. The concentrated solution so produced by boiling oil water may be returned to the sump through the pipe 60. Cooling and interchange means may be provided at 6| to conserve sensible heat of the boiled liquid. u

The latent heat taken up by condensation of water in the liquid may be removed from the circulating liquid in the main circulating stream by means of the cooler 1I, which may be cooled by water or other cooling media the supply of which to the cooler may be controlled in any suitable 'mannen Means may be provided to control the supply of liquid from sump 53 to the regenerating boiler 51 where water is removed by evaporation. This means may consist of a density control unit in the chamber 50 connected by connections 8l with valve 62 to operate the valve in response to changes in density of the liquid. Other connections may be provided to control the regenerating rate, that is, the rate in which condensed water is removed through the vent 58 so that the density of the circulated liquid inthe main stream remains constant. The drying unit 50 is operated in such a way as to reduce the relative humidity of the air leaving the unit to a low value as will be more clearly specied hereafter. A duct or connection 63 leads from the space of occupancy i and 2, to the entrance of the drying chamber 50, and dampers 64, 65 allow for the regulation of the proportion of air drawn from the space of occupancy through the duct 63 and the proportion of air drawn from the outside through the duct I1 which enters the drying space 50.

A thermostatic control responsive to the temperature of the air in the space to be conditioned may be connected with the source of ,cooling to control the temperature on the cooling coils 3 i, The cooling source is shown as a refrigerating machine 9|, but any form of cooling device may be used, including cooling by cold water. A humidostat S00 may be connected with the drying apparatus so as to controi the humidity in the space by controlling either the density of the circulated brine or by shutting off the brine when. the humidity in the space I is less than is desired and by turning on the brine when the humidity in space I is greater than is desired; or it is possible to control the dampers in such a way as to proportion the amount of air which passes through the drying chamber so as to maintain the humidity in the space I at the desired condition.

The foregoing constitutes a description of a preferred form of apparatus andthe following description serves as an example illustrating its mode of operation. This mode of operation together with the result is most convenientlyset forth by following through the changes in condition of the air in the various parts of the apparatus on a psychrometric chart, marked in accordance with the example shown. Reference is here had to Fig. 2 of the accompanying drawing illustrating such a chart. In the example chosen for illustration, the outside air has a relative humidity of 45% and a temperature of 90 degrees, this state of the outside air vbeing illustrated on the chart by the point A. The desired inside air involves a temperature of 80 degrees and a relative humidity of 40% and the point on the chart corresponding to these conditions is marked B. A calculation of the heat and moisture load shows that with the desired amount of circulating air the necessary conditions of temperature and humidity for the air entering the place of occupancy was 65 degrees and a relative humidity of 60%. The point in the chart corresponding to this condition is marked C. It was considered desirable to introduce into the air stream 30% fresh air. If this problem is worked out on the usual basis of removing the heat and moisture by means of refrigeration alone, it can be shown that it is necessary to cool a portion of the air, approximately 60% of the air, to 40 degrees F., and return that portion of the air to the main circulating stream so that the air entering the place of occupancy will have the necessary temperature of 65 degrees and a relative humidity of 65%. It can be shown that if this is done, approximately 35% of the refrigeration is used to condense the water content of the air.

If now instead of using refrigeration alone, a comf bination of refrigeration and drying is employed in accordance with my invention, and if the drying is applied to the intake air alone, and if we assume that the temperature of cooling water available is such that it is practical to dry the air at 90 degrees F., the temperature of the mixture of air obtained in the mixing chamber I9 by mixing r10% of air at 80 degrees and 20% of air at 90 degrees will be 82 degrees. Since no moisture is removed by the refrigerating portion of the apparatus when working in accordance with my invention, the moisture content of the mixed air must be retained as the moisture content of the air desired, namely, at the temperature of 82, the mixed air will have a relative humidity of 35%, and will have the state E. To obtain this relative humidity, the air leaving the drying chamber will be on the line BE where that line extended cuts the line of 90 F. It therefore must have a relative humidity of approximately 21% which relative humidity it is practical to obtain in an apparatus of this kind. The air of this composition is represented by the point F on the psychrometric chart and the mixed air containing air of the composition F and air of the composition B will have the composition E as shown in the psychrometric chart. If the air of the composition E is then cooled without removal of moisture, its state will change from the state E to the state C, which is the desired state for air entering the chamber in order to maintain the condition B in the chamber. Operating in this manner, the total refrigeration load will be approximately 65% of the total refrigeration load in this example Where refrigeration alone is used. In order to obtain these results with an automatic apparatus, it is suflicient to connect the thermostat 90 so that it controls the amount of refrigeration supplied to the air in accordance with demands in the usual manner except that it is desir-able to set the refrigerating apparatus so that the temperature can never fall below the dew point, or the device I5 responsive to dew point of the air can be employed to keep the temperature of the coils 3|, 32 above the dew point. In order to obtain the desired humidity, the density of the circulating liquid may be set at a constant value suilicient to obtain air of the expected minimum humidity required. The temperature of the circulating drying liquid may then be allowed to vary responsive to the indications of a humidostat |00 placed in the place of occupancy so that when the humidity falls below the desired value, the temperature of the circulating liquid in 1I will rise and so that when the humidity rises above the desired value, the temperature of the drying liquid will fall.

From the foregoing description of the method, apparatus and mode of operation of the invention, it will be observed that provision is made for discharging into the atmosphere outside of the enclosure a portion of the air from the enclosure or place of occupancy, whereas the remainder of the air from the enclosure supplies an air stream passing from the enclosure and aliases through the conditioning apparatus before it is returned to the enclosure or place of occupancy. In its passage, this air stream is cooled in a cooling space wherein the-cooling is automatically controlled in accordance with the desired condition. Fresh make-up air is taken from outside the enclosure, is dried to a predetermined condition, and is then added to the air stream i replacing the air discharged from the enclosure to the atmosphere. This fresh make-up air is dried in drying apparatus controlled in accord` ance with the conditioning desired and may form all of the dried air added in the cooled recirculating air stream, or it may be commingled in` controlled proportion with a certain amount of air passed from the enclosure through the drying apparatus before such air is returned to the cooled recirculating air stream. v

While the invention is hereinabove described in connection with the preferred embodiment, it is to be understood that the words which have been used are words of description rather than of limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of the invention in all of its aspects.

I claim: i l

In combination apparatus for air conditioning an enclosure comprising; drying means for contacting controlled quantities of fresh outside air and air from the enclosure with a liquid drying solution, means for unitingand refrigerating without drying a controlled stream of air from the enclosure and the mixed air from the drying means, means for returning the air from the refrigerating means to the enclosure, means including a thermostat responsive to temperature withinthe enclosure for controlling the refriger ating means, means including a humidostat responsive to humidity in the enclosure for maintaining a predetermined drying effect by the liquid drying solution in the drying means, and means responsive tothe dew point of the air leaving the refrigerating means for controlling the minimum temperature of the refrigerating means. A L,

FRANCIS R. BICHOWSKY. 

